Silencer for firearms, combustion engines, and the like



H. coANDA 2,046,017

COMBUSTION ENGINES AND THE LIKE June 30, 1936.

SILENCER FOR FIREARMS,

Filed April 19, 1955 R @www TN E NA W :V6 w mc M m, l/'l 0 MMM" MH 1jr E \\\\\\M`\ 4l /lll'r HH N,

Patented June 30, 1.1"936 UNITED STATES smENcER Fon FmEARMs,

ENGINES, AND THE L COMBUSTION IKE Henri Guanda, Clichy, France Application April 19, 1935, Serial No. 17,362 -In France October 8, 1934 7 Claims.

Ihis invention relates to 'silencing devices for re arms, combustion engines and the like and has for its Aobject to provide an improved yarrangement for silencing the outow of a stream of gas issuing from a tube or other outlet into the surrounding atmosphere. My invention is based upon the lamination of said 'gas stream into thin sheets.

If a gas flowing vat high velocity is/ projected into the atmosphere through a very narrow slit, the sheet which escapes through said slit can be given a, predetermined direction by braking it on the desired side, the optimum curve to be described by the outflowing'sheet of gas being a function of the physical constants of said gas and of those of the surrounding atmosphere, as well as of the velocity and mass of the gas stream. By suitably choosing these factors, it is therefore possible thus to` change the direction of the direct reaction ,of the gases escaping into the surrounding atmosphere, and to permit their escape without noise.

^ If the gases are guided for a substantially long period,l so that their expansion may absorb part of their heat, which further facilitates their evacuation, there is obtained both' an improvement in efficiency and outlet vvelocity and the' absence of noise.

, In the case of silencers for firearms or for combustion engines it will therefore-be sufficient to provide in the path of the gases an escape towards a chamber,l this chamber being provided with slits so arranged and constructed that they impart to the sheets of ,gas escaping into the atmosphere a predetermined direction due to braking of the gaseous sheet on one side thereof. In this manner the shock wave which occasions the sharpfreport of fire-arms, guns, etc., is wholly eliminated.

The silencers for firearms or` combustion engines according to the present invention therefore include a. chamber which' may eventuallyn serve for the partial expansion of the gases,into which the exhaust pipe or the barrel of a gun 'or firearm opens through a series of suitably arranged orifices, said collecting chamberin turn opening intothe atmosphere through a series of narrow slits, the outer surface o f said chamber being provided with projections of curved section each of which is provided on only one side of a. respective slit. f

In ordr that the invention may be more clearly understood a, silencer for a firearm and for a combustion'` engine Will now. be described with reference to the accompanying drawing wherein (ci. 181-60) I Fig. 1 is a section through a. fire arm silencer,

Fig. 2 is a-detail of Fig. 1, Fig. 3 is a section through a combustion engine silencer and Fig. 4 -is a section on the line IV-IV of Fig. 3.

Referring to Fig. 1, the barrel I of a iire ann 5 is provided, at a short distance from its muzzle 2, with annularly arranged orices 3, through which the gases `escape into an expansion chamber 4, formed between the barrel I 'and a sleeve 5 arranged on the barrel. 'I'he expansion chamber l0 4 opens into the atmosphere through substantially narrow slits -6 which are inclined to the axis of the chamber 4.l The outer face of the sleeve 5 is provided witha projection 8 located adjacent the outlet of each of said slits 6 on 15 the side thereof nearest the butt end ofthe gun (see Fig. 2). This projection 8 causes the sheet of gas escaping through slit 6 t"o move substantially tangentially to the walls of the said pro- `jection 8, following the path indicated by the 20 arrow F.

Since these exhaust gases react in the opposite direction to the recoil, they create by their displacement a vacuum at f (Fig. 2) avoiding the creation of a shock yreaction which would 25 propagate itself, as in the case of ordinary lirearms, by giving rise to the well known crack of present day fire arms. In this manner the eiect of the recoilis considerably reduced at the same time as the shock wave is eliminated.

' 30 In Fig. 3 and 4 a similar arrangement is applied to the exhaust gases of combustion engines; the

gases coming from the engine pass through a pipe 9, into the annular expansion chamber l0 which communicates with the atmosphere through slits 35 Il. When the gases escape through slits II they are guided by .projections I2 which are of a shape comparable to those4 described with reference to Fig. 2, and produce the silencing effect. The annular chamber I0 may be constituted by rings I3 40 arranged on an axis I4 and held by means of a fixing nut I5 placed at the end of the axis. Between the various rings I3, spacing washers I6 are arranged, their thickness corresponding to the width of slits I I. The rear part of the silencer is preferably given a proi'lle as shown at I6 in order to facilitate the flow of the gases without 3 the production of eddies.

I claim: f

1. A silencerfor the outflow of gases under pressure from an outlet into the atmosphere, which comprises, in combination, a chamber communicating with said outlet, said chamber being provided with a plurality of narrow passages connecting the inside of said chamber with the outside thereof, said passages opening into the atmosphere in a direction making an angle different municating with said outlet, said chamber being provided-with a plurality of narrow passages connecting the inside of said chamber with the out side thereof, said passages opening into the atmosphere in a direction making an angle of at least 90 with the direction of flow ofthe gases issuing from said outlet and an angle different from zero with the outer surface of said chamber,

and a projection of curved section on the outer surface of said chamber adjacent to each passage on the side thereof corresponding to the direction lfrom which the gases enter said chamber, whereby a portion of the gases escaping from said chamber through said passages are caused to flow along said projectionsin a direction substantially opposed to that in which they ow from said outlet into `said chamber.

3. A silencer for an internal combustion engine which comprises, in combination, a chamber communcating with the exhaust of said engine, said' chamber being of substantially cylindrical shape, said chamber being provided with a plurality of annular slits connecting its inside with the atmosphere surrounding it, said slits-extending radially in a direction transverse to the axis of said chamb'er, and annular projections of curved axial section each adjacent to the Y outlet' of an annular slit on the'outer surface of said chamber, all of said annular projections being on the same sidelof r said slits, respectively, whereby a portion of the exhaust gases escaping from said V"chamber through said slitsare caused to ow alons'said projections. c p

4.` A silencer according to claim 3 in which said chamber is formed of a plurality of ring-shaped 5 elements, means for assembling said elements together, and washers interposed between said elements so as to leave the desired slits between them.

5'. A silencer for a device ejecting gases in sud- 10 den or explosive manner, comprising the combination, ofY an annular chamber of predetermined` length, means for introducing-gases under pressure from said device into said chamber within the annular bounding wall of the latter, 'said l5 bounding wall'being pierced by at least one aperture disposed transversely to the axis of said yannular chamber and intermediate the ends thereof so as to 4connect; the interior of the chamber with the atmosphere and allow gases from said cham` 20 ber to escape throughI said aperture, and a projection of curved section with respect to an axial plane disposed upon the outer surface of said-an-v nular chamber adjacent to the aperture in the bounding wall thereof and providing a. smoothlyu25 curved continuation of solely the forward side 'of the wall of said aperture with respect to the direction of movement of the lgases within the annular chamber', whereby. portion of the gases escaping from/said chamber 'through said aper- 30 ture are caused to flow along the exterior of said projection and then along the exterior of the annular chamber, said aperture making an angle which is at maximum a right angle with respect to the axis of said chamber.

6. A silencer according to claim 5, wherein the bounding wall is pierced by a plurality ofv spaced annular apertures. l

7. A silencer according to claiml, wherein the bounding Wallis pierced by-an annular aperture 40 in the form of a slit.

HENRI COANDA. 

